I keep seeing all these headcanons about the doubles
I honestly thought that it was canon that no one killed their double.
It was just everyone’s city distorting what they saw. For a while Desert Bluffs and Night Vale were one.
Mod note: First, it’s definitely canon that one of the Danas killed the other.
Second, the doubles were all identical to their originals, in every detail. That’s why the surviving Dana doesn’t know if she’s the original or the double. She has the same name, and same memories of living in Night Vale, either way.
We never hear about a single person in Desert Bluffs who is so identical to anyone in Night Vale. (Cecil and Kevin are visually similar, but have different names, and their own personal memories of living in their respective hometowns.)